At present, during a process of replacing an SDH (synchronous digital hierarchy) network with a PTN (packet transport network) network, the PTN network generally needs to be compatible with services, a networking manner and a maintenance mode of the SDH network, so as to implement interworking with the current SDH network, and manage and maintain the SDH network.
The SDH network uses an STM-N frame structure to transmit signals, and the frame structure includes an SOH (section overhead), a management unit pointer and an information payload, where, the SOH includes an RSOH (regenerator section overhead) and an MSOH (multiplex section overhead). In all SOH bytes of the SDH/Sonet, bytes from D1 to D12 are management bytes of the SDH, which are also referred to as DCC (data communications channel) bytes. For ease of managing the SDH network by the PTN network, it is required to transparently transmit the DCC bytes of SDH at two ends of the PTN network in the PTN network.
In the prior art, the DCC bytes are transmitted by using a management packet of a pseudo wire. A Channel Type is set to a specific value in the management packet of the pseudo wire to indicate that the management packet carries the DCC bytes, and meanwhile, the DCC bytes that need to be transparently transmitted are placed into an OAM Packet field for transmitting.
However, the inventor finds that, when the DCC bytes of the SOH are placed into the management packet of the pseudo wire by using the existing method and management information of a service emulated by the pseudo wire is transmitted by using the management packet of the pseudo wire, although the transparent transmission of the DCC bytes may be realized, an intermediate node in the PTN network needs to identify whether the management packet carries the management information of the pseudo wire or the management information of a SDH service, thereby increasing a burden of the intermediate node in the PTN network.